overlay: do not clone source recursively
overlay: do not clone source recursively

do not clone the source directory in recursive mode (the equivalent of
MS_BIND|MS_RECURSIVE) but use only a regular bind mount.  If
not recursive bind mount is used then the existing overlay mounts are
not replicated.  In this way a new idmapped mount won't need to map
the overlay mount as well, causing the mount_settattr(2) syscall to
fail with EINVAL since it is not possible to idmap an overlay mount
yet.

Closes: https://github.com/containers/storage/issues/1308

Signed-off-by: Giuseppe Scrivano <20002b7b24c75512093a71a58285826d5c504fca@redhat.com>

containers/storage,containers/storage,containers/storage